The present invention relates to a system of the type in which a control unit is arranged to selectively address electrical control signals, via a single common transmission link, to a plurality of remote units whereby to selectively activate controlled devices associated with these units. These controlled devices may be actuator means for carrying out respective predetermined operations and/or sensor means for transmitting to the control unit, via the said link, electrical information signals indicative of the value of a respective monitored physical quantity.
The object of the present invention is to provide a system for addressing electrical signals from a control unit to a plurality of remote units of the type outlined above which is simple and economical to manufacture, easy to instal and which has a high degree of reliability and flexibility in use.